Answer:
Step-by-step explanation:
I am assuming that you mean (4,−9) and (8, -3).
Hope this helps.
To find a percentage of a number, multiply by the decimal form of that percentage(20%=0.20). So, take the cost, $430, and multiply by common state sales tax (7% for me)---430 x 0.07 = 30.10 The sale tax rate is 7%.
The answer is 523.6 and all you have to do is round it to the nearest hundredth